了
瞭traditional
(completed action marker); (modal particle indicating change of state, situation now); (modal particle intensifying preceding clause)
unofficial variant of 瞭[liao4]
to finish; (used with 得[de2] or 不[bu4] after a verb to express (im)possibility, as in 忘不了[wang4 bu5 liao3] "cannot forget"); (literary) (usually followed by a negative such as 無|无[wu2] or 不[bu4]) completely (not); entirely (not); (not) in the least; to understand clearly (variant of 瞭|了[liao3])
(of eyes) bright; clear-sighted; to understand clearly
Examples
响了。
算了。
Part of the HSK 1 word list.
Learn 了 the way it sticks: in sentences built from words you already know, scheduled so you review right before you'd forget.
Start your free weekDefinitions adapted from CC-CEDICT (CC BY-SA 4.0, modified). Example sentences from Tatoeba (CC BY 2.0 FR). Frequency ranks from the BCC corpus. Full credits on the Attributions page.